Methods and systems for processing a sucrose crop and sugar mixtures

ABSTRACT

A method comprising: (a) providing a partially processed sucrose crop product containing at least 2% optionally at least 5% of the sucrose content of said crop at harvest on a dry solids basis, cellulose and lignin; (b) hydrolyzing said partially processed crop product with HCl to produce an acid hydrolyzate stream and a lignin stream; and (c) de-acidifying said hydrolyzate stream to produce a de-acidified sugar solution and an HCl recovery stream. Additional, methods, systems and sugar mixtures are also disclosed.

RELATED APPLICATIONS

This application claims the benefit of 35 U.S.C. §119(e) and/or §365(a)from:

U.S. provisional application 61/501,276 filed on Jun. 27, 2011 by AharonEYAL and entitled “Methods of Processing s Sucrose Crop”; and

In accord with the provisions of 35 U.S.C. §119(a) and/or §365(b), thisapplication claims priority from:

prior Israeli application IL206678 filed on 28 Jun. 2010 by Aharon EYALand entitled “A Method for the Production of Fermentable Sugars”; and

prior PCT application IL2011/000130 filed on 6 Feb. 2011 by Aharon EYALet al. and entitled “Methods for the Separation of HCl from aCarbohydrate and Compositions Produced thereby”.

Each of these priority documents is fully incorporated by reference.

This application is also related to the following co-pendingapplications, each of which is fully incorporated herein by reference:

prior Israeli application IL 209912 filed on 9 Dec. 2010 by Aharon EYALet al. and entitled “A Method for Treating a Lignocellulosic FeedContaining Ash and Fatty Acid”; and

prior Israeli application IL 211093 filed on 6 Feb. 2011 by Aharon EYALand entitled “A Method for Processing a Lignocellulosic Material and forthe Production of a Carbohydrate Composition”; and

U.S. 61/473,134 filed 7 Apr. 2011 by Aharon EYAL and entitled“Lignocellulose Conversion Processes and Products”; and

U.S. 61/483,663 filed 7 May 2011 by Aharon EYAL and entitled“Lignocellulose Conversion Processes and Products”

U.S. 61/483,777 filed 9 May 2011 Robert JANSEN et al. and entitled“Hydrolysis Systems and Methods”; and

U.S. 61/487,319 filed 18 May 2011 by Robert JANSEN et al. and entitled“Hydrolysis Systems and Methods”; and

U.S. 61/491,243 filed 30 May 2011 by Robert JANSEN et al. and entitled“Lignin Compositions, Systems and Methods for Processing Lignin and/orHCl”; and

U.S. 61/500,169 filed 23 Jun. 2011 by Aharon EYAL et al. and entitled“Sugar Mixtures and Methods for Production and Use thereof”

FIELD OF THE INVENTION

This invention relates to production of sugars from sucrose crops suchas sugar cane and sugar beets.

BACKGROUND OF THE INVENTION

Sugarcane is a major source of sucrose, which is mostly used in food(after refinement) or as a fermentable carbohydrate to produce ethanol.Sucrose is a hetero-disaccharide of glucose and fructose.

Sucrose is typically manufactured from sugarcane in a process thatcomprises chopping, shredding, and milling by crushing and macerating inroller mills and in some cases comprises extracting the sucrose bydiffusion. Milling is typically performed at temperatures of up to 60°C. and extraction by diffusion is typically performed at temperatures ofup to about 80° C. The combined operations for the recovery of sucrosefrom sugarcane are referred to in the following as sucrose extraction.

Sucrose extraction efficiency depends on many factors, including, interalia, the amount of fiber in the sugarcane. Typically more than 90% ofthe sucrose content of the sugarcane is extracted out of the biomassmaterial. More typically more than 95% of the sucrose content isextracted.

Sugarcane juice comprises mainly sucrose, however as a result of theconditions of the process some of the sucrose is inverted into fructoseand glucose.

The remaining biomass, after processing, is referred to as sugarcanebagasse or bagasse. Typically, bagasse comprises (on a washed and driedbasis); 45%-55% wt cellulose, 20%-25% wt hemicellulose and 18%-24% wtlignin. Additional components such as ash and waxes are less than 5% wt.

Bagasse is mainly used for providing energy (more than sufficient forthe sugar mill), to generate electricity by burning, as cattle feed andfor intermediate and low quality paper. Bagasse could theoretically beused for the production of fermentable carbohydrates, e.g. for theproduction of ethanol. Yet, existing methods for producing fermentablecarbohydrates from bagasse are not considered industrially feasible.

In the sugar industry, cane delivered to the processing plant is calledburned and cut (b&c), and represents 77% of the mass of the raw cane.The remaining 23% includes the leaves (which are burned and whose ashesare left in the field as fertilizer), and the roots that remain in theground to sprout for the next crop. Each ton of b&c cane yields 740 kgof juice (about 135 kg of sucrose and about 605 kg of water) and 260 kgof moist bagasse (130 kg of dry bagasse).

Sugar beets are another important source of sucrose. Sugar beets accountfor roughly 30% of the world's sugar production. The European Union, theUnited States, and Russia are the world's three largest sugar beetproducers. The European Union and Ukraine are significant exporters ofsugar from beets.

In this specification some solvents are defined in terms of a Hoy'scohesion parameter. By way of review, Delta-P is the polarity relatedcomponent of Hoy's cohesion parameter and delta-His the hydrogen bondingrelated component of Hoy's cohesion parameter.

The cohesion parameter, as referred to above or, solubility parameter,was defined by Hildebrand as the square root of the cohesive energydensity:

$\delta = \sqrt{\frac{\Delta\; E_{vap}}{V}}$

where ΔEvap and V are the energy or heat of vaporization and molarvolume of the liquid, respectively. Hansen extended the originalHildebrand parameter to a three-dimensional cohesion parameter.According to this concept, the total solubility parameter, delta, iscomposed of three different components, or, partial solubilityparameters relating to the specific intermolecular interactions:δ²=δ_(d) ²+δ_(p) ²+δ_(h) ²

in which delta-D, delta-P and delta-H are the dispersion, polarity, andHydrogen bonding components, respectively. Hoy proposed a system toestimate total and partial solubility parameters. The unit used forthose parameters is MPa^(1/2). A detailed explanation of that parameterand its components can be found in “CRC Handbook of SolubilityParameters and Other Cohesion Parameters”, second edition, pages122-138. That and other references provide tables with the parametersfor many compounds. In addition, methods for calculating thoseparameters are provided.

SUMMARY OF THE INVENTION

A broad aspect of some embodiments of the invention relates to potentialinteractions between the table sugar (i.e. crystalline sucrose) industryand the sugar conversion industry. “Sugar conversion” as used in thisspecification and the accompanying claims indicates chemical orenzymatic conversion of saccharides to other molecules, including, butnot limited to, alcohols, fatty acids, amino acids, carboxylic acids,proteins and monomeric feedstocks for the polymer industry andprecursors for such monomeric feedstocks. In some exemplary embodimentsof the invention, enzymatic conversion is accomplished by fermentation.

As used in this specification and the accompanying claims, the term“sugar” indicates a water soluble carbohydrate and includesmonosaccharides, disaccharides, and higher oligosaccharides of up toabout 10, optionally 11, optionally 12 saccharide units. Many exemplaryembodiments of the invention relate specifically to the disaccharidesucrose and its component monosaccharides glucose and fructose.

One aspect of some embodiments of the invention relates to partiallyprocessing a sucrose crop such as sugar cane or sugar beets so that apredetermined amount of sucrose is retained in a partially processedcrop product.

Another aspect of some embodiments of the invention relates tohydrolyzing a sucrose crop with all of its sucrose content.

The phase “processing a sucrose crop” indicates separation of at least aportion of the sucrose into a “sugar juice” and a residual product. Inthe case of sugar cane, the residual product is conventionally referredto as bagasse. In the case of sugar beets, the residual product isreferred to as spent cossettes. “Bagasse” and “Cossettes” producedaccording to various exemplary embodiments of the invention will have asignificantly higher sucrose content than corresponding “normal”products.

As used in this specification and the accompanying claims, the terms“partially processed” and “partial processing” indicate that a portionof the sucrose present in the crop which would normally appear in thesugar juice (according to conventional industrial methods) is purposelyleft in the residual product.

In some exemplary embodiments of the invention, sugar cane is processedso that at least 2%, optionally at least 5% of its sucrose content isretained in the crushed cane. In some exemplary embodiments of theinvention, the partial processing is conducted on b&c cane. In otherembodiments, the sugar cane is cut without burning so that cellulose inthe leaves is not lost.

Since b&c cane is typically about 13% sucrose, this partially processedcane contains at least about 6.5 kilograms of sucrose per ton if b&ccane is used as a starting material. If the leaves are not burned away,the sugar values will be lower by about 20 to 25% because the leafyportion of the cane contains little or no sucrose. There is a tradeoffbetween the potential value of sugars available from hydrolysis ofcellulose in the leaves and complications caused by the leaves in theprocessing of cane to extract sugar juice.

In other exemplary embodiments of the invention, sugar beets areprocessed so that at least 2%, optionally at least 5% of their sucrosecontent is retained in the cossettes after diffusion. In some exemplaryembodiments of the invention, the partial processing is conducted onbeets with leaves attached so that cellulose in the leaves is not lost.

Assuming that sugar beets contain about 11.5% extractable sucrose, thispartially processed crop product contains about 5.75 kilograms ofsucrose per ton. If the leaves are not removed, the sugar values will beproportionally lower because the leafy portion of the beet plantcontains little or no sucrose. There is a tradeoff between the potentialvalue of sugars available from hydrolysis of cellulose in the leaves andcomplications caused by the leaves in the processing of beets to extractsugar juice.

In some exemplary embodiments of the invention 13, optionally 15,optionally 20, optionally 25, optionally 30, optionally 35, optionally40 kilograms/ton of sucrose are left in the partially processed cropproduct. Optionally, this measurement is on a dry matter basis.

Optionally, the partially processed cane is provided as part of anaqueous slurry. Such a slurry will have a lower sugar concentration, butthe values given above “per ton of partially processed cane” still applyto that portion of the slurry made up of cane. In some exemplaryembodiments of the invention, an increase in amount of sucrose left inthe partially processed cane contributes to an increase in economicvalue of the partially processed cane. Alternatively or additionally, anincrease in amount of sucrose left in the partially processed canecontributes to a decrease in price per unit of sucrose produced from thecane by conventional sugar refining methods.

Another aspect of some embodiments of the invention relates tohydrolyzing the partially processed cane. In some exemplary embodimentsof the invention, this hydrolysis is an acid hydrolysis. Optionally, HClis employed as the acid.

Acid hydrolysis produces an acid hydrolyzate containing a mixture ofsugars. Some of these sugars originate from hydrolysis of hemicelluloseand/or cellulose. Some of these sugars result from inversion of thesucrose originally present in the partially processed cane.

Another aspect of some embodiments of the invention relates tode-acidification of the acid hydrolyzate. In some exemplary embodimentsof the invention, de-acidification is by selective extraction of HClwith an extractant including a suitable solvent or combination ofsolvents. Optionally, de-acidification is with an extractant includingan S1 solvent. For purposes of this specification and the accompanyingclaims an “S1 solvent” or “S1” indicates a solvent characterized by awater solubility of less than 10% and by at least one of (i) having adelta-P between 5 and 10 MPa^(1/2) and (ii) having a delta-H between 5and 20 MPa^(1/2). In some exemplary embodiments of the invention, HClselectively transfers to the extractant containing S1 upon contacttherewith.

In some exemplary embodiments of the invention, the de-acidificationprocess includes an additional extraction. Optionally, the extractant inthis additional extraction includes an S2 solvent. For purposes of thisspecification and the accompanying claims an “S2 solvent” or “S2”indicates a solvent characterized by a water solubility of at least 30%and by at least one of (i) having a delta-P greater than 8 MPa^(1/2) and(ii) having a delta-H greater than 12 MPa^(1/2). In some exemplaryembodiments of the invention, HCl selectively transfers to theextractant containing S2 upon contact therewith.

Another aspect of some exemplary embodiments of the invention relates torecovery of energy from sugar cane as heat. Optionally, heat energy canbe recovered by combustion of leaves and/or tops and/or residual lignin.According to various exemplary embodiments of the invention this heatenergy is used in one or more industrial processes associated withrefining of sucrose from sugar juice and/or hydrolytic processing ofpartially processed sugar cane.

Optionally, a portion of the heat energy can be used to generateelectricity. This electricity can be used either within a processingplant, or routed to a regional power grid. In some exemplary embodimentsof the invention, this electricity is used for ancillary functionswithin a plant such as lighting and climate control.

Another aspect of some exemplary embodiments of the invention relates toa system which produces crystalline sucrose, a saccharide richhydrolyzate and combustible lignin from received sugar cane. In someexemplary embodiments of the invention, an initial acid hydrolyzate isde-acidified by extraction with a solvent, optionally provided as partof an extractant with one or more additional components. Optionally, thesolvent and/or recovered acid and/or additional components is recycled.In some exemplary embodiments of the invention, the de-acidificationprocedure increases a total saccharide concentration and/or reduces aconcentration of an impurity in the hydrolyzate.

It will be appreciated that the various aspects described above relateto solution of technical problems related to the role of sucrose inpreparation of downstream conversion products from sugar cane. Prior tothis application, it was widely believed that sucrose should beextracted as efficiently as possible and refined prior to conversion.

Alternatively or additionally, it will be appreciated that the variousaspects described above relate to solution of technical problems relatedto conversion of hemicellulose and cellulose in sugar cane to desiredconversion products.

Alternatively or additionally, various exemplary embodiments of theinvention solve the technical problem of reducing overall greenhouse gasemissions. In some exemplary embodiments of the invention, thisreduction occurs during combustion of fuel (e.g. ethanol). Alternativelyor additionally, this reduction occurs during production. Reductions ofgreenhouse gas emissions can be achieved, for example, by burning sugarcane leave in a processing plant and harvesting released heat energyand/or by processing lignin to create a clean burning product whiletransforming cellulose to fermentable sugars which are a pre-cursor ofcombustible fuels such as alcohols. Alternatively or additionally,reducing overall greenhouse gas emissions may occur as a result of usingacid hydrolysis as a partial substitute for refining of gasoline ordiesel fuel.

In some exemplary embodiments of the invention, there is provided amethod including:

(a) providing a harvested crop containing an amount of sucrose;

(b) processing the harvested crop to produce sugar juice containingsucrose and partially processed crop product, the product including atleast 2%, optionally at least 5% of the amount of sucrose.

Optionally, the harvested crop includes burned and cut (b&c) sugar cane.

Optionally, the harvested crop includes sugar cane with leaves.

Optionally, the harvested crop includes sugar beets.

Optionally, the method includes burning a leafy portion of the harvestedcrop

to release heat energy and produce ashes; and using the heat energy forat least one process selected from the group consisting of theprocessing, refining of sucrose from the sugar juice produced anddistillation.

Optionally, the method includes fertilizing a field using at least aportion of the ashes.

In some exemplary embodiments of the invention, there is provided amethod including:

(a) providing a partially processed crop product containing at least 2%,optionally at least 5% of the sucrose content of the crop at harvest ona dry solids basis, cellulose and lignin;

(b) hydrolyzing the partially processed crop product with HCl to producean acid hydrolyzate stream and a lignin stream; and

(c) de-acidifying the hydrolyzate stream to produce a de-acidified sugarsolution and an HCl recovery stream.

Optionally, the partially processed sucrose crop product comprises sugarcane leaves and/or tops.

Optionally, the partially processed sucrose crop product comprises sugarbeet leaves.

Optionally, the de-acidified sugar solution includes at least 90% of atheoretical yield of sugars from said at least 2%, optionally at least5% of the sucrose content.

Optionally, the de-acidified sugar solution includes 90% of atheoretical yield of sugars from the cellulose.

Optionally, a weight/weight ratio between hydroxymethylfurfural andsugars in the hydrolyzate is less than 0.01

Optionally, a weight/weight ratio between hydroxymethylfurfural andsugars in the de-acidified sugar solution is less than 0.002.

Optionally, a weight/weight ratio between furfural and sugars in thehydrolyzate is less than 0.01.

Optionally, a weight/weight ratio between furfural and sugars in thede-acidified sugar solution is less than 0.002.

Optionally, the HCl recovery stream includes at least 95% of the HCl inthe hydrolyzate.

Optionally, the method includes concentrating HCl from the HCl recoverystream to a concentration of at least 35% wt.

Optionally, the hydrolyzing includes contacting the partially processedcrop product with the HCl in a counter-current mode of operation.

Optionally, the method includes collecting gaseous HCl from the HClrecovery stream; and contacting the gaseous HCl with the partiallyprocessed crop product or with water.

Optionally, the hydrolysis is conducted at a temperature lower than 20°C.

Optionally, the hydrolysis is conducted at a temperature lower than 15°C.

Optionally, the acid hydrolyzate is characterized by:

(i) a ratio of sugars to water in the range of 0.2 to 2.0 by weight; and

(ii) a ratio of HCl to water of at least 0.17, optionally at least 0.33

Optionally, the ratio of HCl to water is at least 0.5, optionally atleast 0.6.

Optionally, the ratio of HCl to water is not more than 0.85.

Optionally, the de-acidifying of the hydrolyzate includes:

(a) extracting the hydrolyzate, with a first extractant including afirst solvent (S1) to produce to an HCl-carrying first extract and anHCl-depleted sugar solution;

(b) recovering HCl from the HCl-carrying first extract;

Optionally, the method includes extracting the HCl-depleted sugarsolution with a second extractant including S1 and a second solvent S2.

Optionally, the HCl-carrying first extract includes sugars, andincluding:

contacting the HCl-carrying first extract with a recycled aqueous HClsolution, prior to the recovering.

Optionally, S1 is selected from the group consisting of alcohols,ketones and aldehydes having at least 5 carbon atoms and combinationsthereof.

Optionally, the second extractant is characterized by at least one of:

(i) a polarity related component of Hoy's cohesion parameter (delta-P)greater than the delta-P of the first extractant by at least 0.2MPa^(1/2)′ and

(ii) a hydrogen-bond related component of Hoy's cohesion parameter(delta-H) greater than the delta-H of the first extractant by at least0.2 MPa^(1/2).

Optionally, the first extractant includes S2 and wherein a ratio ofS2:S1 in the second extractant is greater than a same ratio in the firstextractant by at least 10%.

Optionally, the method includes generating at least a fraction of thefirst extractant from an organic phase composition by removing S2therefrom.

Optionally, the de-acidifying the hydrolyzate reduces a concentration ofat least one non-saccharide impurity in the hydrolyzate by at least 30%on a weight basis relative to the sugars.

Optionally, the method includes de-acidifying the lignin stream to formrecovered HCl and de-acidified lignin.

Optionally, the method includes burning the de-acidified lignin toprovide heat energy.

Optionally, the method includes using the heat energy for at least oneprocess selected from the group consisting of processing a harvestedcrop, refining of sucrose from a sugar juice produced during theprocessing and distillation.

Optionally, the partially processed crop product is produced fromunburned sugar cane.

Optionally, the partially processed crop product is produced from sugarbeets without removal of leaves.

In some exemplary embodiments of the invention, there is provided asystem including:

(a) a sucrose extraction module adapted to separate sucrose from areceived crop to produce a partially processed crop product containingresidual sucrose and a raw juice including sucrose;

(b) a hydrolysis module which receives the partially processed crop andbrings it into contact with a concentrated acid to produce an acidhydrolyzate and residual lignin; and

(c) an acid recovery module which receives the acid hydrolyzate andseparates it to produce an acid recovery stream and a de-acidifiedhydrolyzate.

Optionally, the system includes a pre-extraction module adapted toextract at least a portion of ash from the received crop prior tointroduction into the sucrose extraction module.

Optionally, the system includes a pre-combustion module adapted to burna portion of the received crop to release heat energy prior tointroduction into the sucrose extraction module.

Optionally, the system includes a sucrose refinery adapted to producecrystallized sucrose from the raw juice.

Optionally, the system includes a lignin de-acidification module adaptedto separate acid from the residual lignin to produce combustible ligninand recovered acid.

Optionally, the system includes a lignin-combustion module adapted toreceive and burn the combustible lignin to release heat energy.

In some exemplary embodiments of the invention, there is provided amixture of sugars characterized by a ratio of fructose to mannose of atleast 0.4. Optionally, the ratio of fructose to mannose does not exceed4.8.

In some exemplary embodiments of the invention, there is provided amixture of sugars characterized by a ratio of fructose to xylose of atleast 0.4. Optionally, the ratio of fructose to mannose does not exceed4.6.

In some exemplary embodiments of the invention, there is providedamixture of sugars characterized by a ratio of fructose to galactose ofat least 0.3. Optionally, the ratio of fructose to galactaose does notexceed 3.2.

In some exemplary embodiments of the invention, there is provided amixture of sugars characterized by a ratio of fructose to arabinose ofat least 1.0. Optionally, the ratio of fructose to arabinose does notexceed 11.

-   -   Optionally, a ratio of fructose to total dimeric sugars is at        least 0.05.    -   Optionally, the ratio of fructose to total dimeric sugars does        not exceed 0.6.    -   Optionally, a ratio of fructose to total monomeric sugars is at        least 0.023. Optionally, the ratio of fructose to total        monomeric sugars does not exceed 0.2.    -   Optionally, the mixture includes hydroxymethylfurfural (HMF).

In some exemplary embodiments of the invention, there is provided amethod including:

-   (a) providing a culture medium including a mixture as described    above; and-   (b) growing an organism in the medium to produce a fermentation    product.

Optionally, the fermentation product includes at least one memberselected from the group consisting of alcohols, carboxylic acids, aminoacids, monomers for the polymer industry and proteins.

Optionally, the method includes processing the fermentation product toproduce a product selected from the group consisting of detergent,polyethylene-based products, polypropylene-based products,polyolefin-based products, polylactic acid (polylactide)-based products,polyhydroxyalkanoate-based products and polyacrylic-based products.

Optionally, the detergent includes a sugar-based surfactant, a fattyacid-based surfactant, a fatty alcohol-based surfactant, or acell-culture derived enzyme.

Optionally, the polyacrylic-based product is selected from plastics,floor polishes, carpets, paints, coatings, adhesives, dispersions,flocculants, elastomers, acrylic glass, absorbent articles, incontinencepads, sanitary napkins, feminine hygene products, and diapers.

Optionally, the polyolefin-based products are selected from milk jugs,detergent bottles, margarine tubs, garbage containers, water pipes,absorbent articles, diapers, non wovens, HDPE toys and HDPE detergentpackagings.

Optionally, the polypropylene based products are selected from absorbentarticles, diapers and non wovens.

Optionally, the polylactic acid based products are selected frompackaging of agriculture products and of dairy products, plasticbottles, biodegradable products and disposables.

Optionally, the polyhydroxyalkanoate based products are selected frompackaging of agriculture products, plastic bottles, coated papers,molded or extruded articles, feminine hygiene products, tamponapplicators, absorbent articles, disposable nonwovens and wipes, medicalsurgical garments, adhesives, elastometers, films, coatings, aqueousdispersants, fibers, intermediates of pharmaceuticals and binders.

Optionally, the fermentation product includes at least one member of thegroup consisting of ethanol, butanol, isobutanol, a fatty acid, a fattyacid ester, a fatty alcohol and biodiesel.

Optionally, the method includes processing of the fermentation productto produce at least one product selected from the group consisting of anisobutene condensation product, jet fuel, gasoline, gasohol, dieselfuel, drop-in fuel, diesel fuel additive, and a precursor thereof.

Optionally, the gasohol is ethanol-enriched gasoline or butanol-enrichedgasoline.

Optionally, the product is selected from the group consisting of dieselfuel, gasoline, jet fuel and drop-in fuels.

In some exemplary embodiments of the invention, there is provided aproduct, a precursor of a product, or an ingredient of a productproduced from a fermentation product produced by a method as describedabove.

In some exemplary embodiments of the invention, there is provided aproduct, a precursor of a product, or an ingredient of a productincluding at least one fermentation product produced by a as describedabove, wherein the at least one fermentation product is selected fromthe group consisting of carboxylic and fatty acids, dicarboxylic acids,hydroxylcarboxylic acids, hydroxyl di-carboxylic acids, hydroxyl-fattyacids, methylglyoxal, mono-, di-, or poly-alcohols, alkanes, alkenes,aromatics, aldehydes, ketones, esters, biopolymers, proteins, peptides,amino acids, vitamins, antibiotics, and pharmaceuticals.

Optionally, the product is ethanol-enriched gasoline, jet fuel, orbiodiesel.

Optionally, the product has a ratio of carbon-14 to carbon-12 of about2.0×10⁻¹³ or greater.

Optionally, the product includes an ingredient as described above and anadditional ingredient produced from a raw material other thanlignocellulosic material.

Optionally, the ingredient and the additional ingredient produced from araw material other than lignocellulosic material are essentially of thesame chemical composition.

Optionally, the product includes a marker molecule at a concentration ofat least 100 ppb.

Optionally, the marker molecule is selected from the group consisting offurfural, hydroxy-methyl furfural, products of furfural orhydroxy-mathylfurfural condensation, color compounds derived from sugarcaramelization, levulinic acid, acetic acid, methanol, galcturonic acid,and glycerol.

In some exemplary embodiments of the invention, there is provided amethod including

-   (a) providing a harvested sucrose crop containing sucrose, cellulose    and lignin;-   (b) hydrolyzing the harvested sucrose crop with HCl to produce an    acid hydrolyzate stream and a lignin stream; and-   (c) de-acidifying the hydrolyzate stream to produce a de-acidified    sugar solution and an HCl recovery stream.

Optionally, the harvested sucrose crop includes sugar cane leaves andoptionally tops.

Optionally, the harvested sucrose crop includes sugar beet leaves.

Optionally, the de-acidified sugar solution includes at least 90% of atheoretical yield of sugars from the sucrose.

Optionally, a weight/weight ratio between hydroxymethylfurfural andsugars in the hydrolyzate is less than 0.01.

Optionally, a weight/weight ratio between hydroxymethylfurfural andsugars in the de-acidified sugar solution is less than 0.002.

Optionally, a weight/weight ratio between furfural and sugars in thehydrolyzate is less than 0.01.

Optionally, a weight/weight ratio between furfural and sugars in thede-acidified sugar solution is less than 0.002.

Optionally, the HCl recovery stream includes at least 95% of the HCl inthe hydrolyzate.

Optionally, the hydrolyzing includes contacting the harvested sucrosecrop with the HCl in a counter-current mode of operation.

Optionally, the hydrolyzing is conducted at a temperature lower than 20°C.

Optionally, the hydrolyzing is conducted at a temperature lower than 15°C.

Optionally, the de-acidifying the hydrolyzate reduces a concentration ofat least one non-saccharide impurity in the hydrolyzate by at least 30%on a weight basis relative to the sugars.

In some exemplary embodiments of the invention, there is provided amethod including

-   -   (a) providing a substrate including cellulose;    -   (b) hydrolyzing the substrate with HCl to produce an acid        hydrolyzate stream;    -   (c) de-acidifying the hydrolyzate stream to produce a        de-acidified sugar solution and an HCl recovery stream; and    -   (d) enzymatically converting at least a portion of glucose in        the de-acidified sugar solution to produce a fructose enriched        sugar solution.    -   Optionally, the substrate includes sucrose.    -   Optionally, the method includes chromatographically separating        the fructose enriched sugar solution to produce a fructose cut        and a glucose cut.    -   Optionally, the method includes enzymatically converting at        least a portion of glucose in said glucose cut to produce        additional fructose enriched sugar solution.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although suitable methods andmaterials are described below, methods and materials similar orequivalent to those described herein can be used in the practice of thepresent invention. In case of conflict, the patent specification,including definitions, will control. All materials, methods, andexamples are illustrative only and are not intended to be limiting.

As used herein, the terms “comprising” and “including” or grammaticalvariants thereof are to be taken as specifying inclusion of the statedfeatures, integers, actions or components without precluding theaddition of one or more additional features, integers, actions,components or groups thereof. This term is broader than, and includesthe terms “consisting of” and “consisting essentially of” as defined bythe Manual of Patent Examination Procedure of the United States Patentand Trademark Office.

The phrase “consisting essentially of” or grammatical variants thereofwhen used herein are to be taken as specifying the stated features,integers, steps or components but do not preclude the addition of one ormore additional features, integers, steps, components or groups thereofbut only if the additional features, integers, steps, components orgroups thereof do not materially alter the basic and novelcharacteristics of the claimed composition, device or method.

The term “method” refers to manners, means, techniques and proceduresfor accomplishing a given task including, but not limited to, thosemanners, means, techniques and procedures either known to, or readilydeveloped from known manners, means, techniques and procedures bypractitioners of architecture and/or computer science.

Percentages (%) of chemicals typically supplied as powders or crystals(e.g. sugars) are W/W (weight per weight) unless otherwise indicated.Percentages (%) of chemicals typically supplied as liquids (e.g. HCl)are also W/W (weight per weight) unless otherwise indicated.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to understand the invention and to see how it may be carriedout in practice, embodiments will now be described, by way ofnon-limiting example only, with reference to the accompanying figures.In the figures, identical and similar structures, elements or partsthereof that appear in more than one figure are generally labeled withthe same or similar references in the figures in which they appear.Dimensions of components and features shown in the figures are chosenprimarily for convenience and clarity of presentation and are notnecessarily to scale. The attached figures are:

FIG. 1 is schematic overview of a system according to some exemplaryembodiments of the invention;

FIG. 2 is a simplified flow diagram of a method according to someexemplary embodiments of the invention;

FIG. 3 is a simplified flow diagram of a method according to someexemplary embodiments of the invention;

FIG. 4 is a simplified flow diagram of a method according to someexemplary embodiments of the invention;

FIG. 5 is a simplified flow diagram of exemplary methods for furtherprocessing of the product produced by the method depicted in FIG. 4according to some exemplary embodiments of the invention;

FIG. 6 is a simplified flow diagram of a method according to someexemplary embodiments of the invention; and

FIG. 7 is a simplified flow diagram of a method according to someexemplary embodiments of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the invention relate to systems and methods whichcoordinate production of crystalline sucrose (table sugar) withproduction of a hydrolysate rich in saccharides from a harvested sucrosecrop. Sucrose crops include, but are not limited to sugar cane and sugarbeets.

Specifically, some embodiments of the invention can be used to a totalvalue of a crop of sugar cane. Other embodiments of the invention can beused to a total value of a crop of sugar beets.

The principles and operation of a system and/or methods according toexemplary embodiments of the invention may be better understood withreference to the drawings and accompanying descriptions.

Before explaining at least one embodiment of the invention in detail, itis to be understood that the invention is not limited in its applicationto the details set forth in the following description or exemplified bythe Examples. The invention is capable of other embodiments or of beingpracticed or carried out in various ways. Also, it is to be understoodthat the phraseology and terminology employed herein is for the purposeof description and should not be regarded as limiting.

Exemplary System

FIG. 1 depicts an exemplary system for processing a harvested sucrosecrop indicated generally as system 100. According to various exemplaryembodiments of the invention the sucrose crop can be sugar cane or sugarbeets.

Depicted exemplary system 100 includes a sucrose extraction module 110adapted to separate sucrose from a received crop 102 to produce apartially processed crop product 112 containing residual sucrose and araw juice 114 comprising sucrose. According to various exemplaryembodiments of the invention the residual sucrose can be 5, 10, 15, 20,25 or 30% or intermediate or greater percentages of an amount of sucrosepresent in received crop 102.

In exemplary embodiments of the invention in which the received crop issugar cane, adaptation involves adjustment of breaking and/or millingparameters.

In exemplary embodiments of the invention in which the received crop issugar beet, adaptation involves adjustment of diffusion parameters.

These adaptations are described in more detail below.

Depicted exemplary system 100 also includes a hydrolysis module 120which receives partially processed crop product 112 and brings it intocontact with a concentrated acid to produce an acid hydrolyzate 122 andresidual lignin 124. In some exemplary embodiments of the invention, theconcentrated acid is HCl. Optionally, the HCl concentration is 37%, 40%,42% or 45% or intermediate or greater percentages as measured on an HClto [HCl+water] W/W basis.

Acid hydrolyzate will include a mixture of soluble sugars includingthose released from hemicellulose and cellulose in received crop 102 aswell as those originating from the residual sucrose. Owing to the highconcentration of acid in hydrolysis module 120, it seems likely thatmost of the residual sucrose in partially processed crop product 112will be inverted to release glucose and fructose. In some exemplaryembodiments of the invention, glucose and fructose resulting fromsucrose inversion are present in acid hydrolyzate 122. In otherexemplary embodiments of the invention, at least a portion of theglucose and fructose resulting from sucrose inversion is present as partof a dimer or longer oligosaccharide.

Depicted exemplary system 100 also includes an acid recovery module 130which receives acid hydrolyzate 122 and separates it to produce an acidrecovery stream 132 and a de-acidified hydrolyzate 134.

The term “raw juice” is used here because it is an art accepted term inthe sugar cane and sugar beet processing industry. However, it will beappreciated that “raw juice” according to various exemplary embodimentsof the invention will be different than a comparable raw juice resultingfrom a process in which a partially processed crop product 112containing residual sucrose is not produced.

In some exemplary embodiments of the invention, system 100 includes anoptional pre-extraction module 140 adapted to extract at least a portionof ash 144 from received crop 102 prior to introduction into saidsucrose extraction module. In these embodiments, received crop 102optionally enters module 140 directly (not depicted). In some exemplaryembodiments of the invention, this pre-extraction is with an extractant142 including a water soluble organic solvent. “Water soluble organicsolvent” as used in this specification and the accompanying claimsindicates a solvent with a solubility in water of at least 50% at 25°C., wherein water has a solubility in the solvent of at least 50% at 25°C. Exemplary water-soluble organic solvents include but are not limitedto ketones and alcohols with up to four carbon atoms. In some exemplaryembodiments of the invention, the solvent includes acetone. Optionally,acetone is the only water soluble organic solvent. Optionally, theextractant is weakly acidic, for example due to presence of sulfurousacid.

In some exemplary embodiments of the invention, the water solubleorganic solvent is recycled. Optionally recycling is by distillation(not depicted).

Ash 144 is separated from the received crop as part of an extract. Thepre-extracted crop 146 is then transferred to sucrose extraction module110 as indicated.

Alternatively or additionally, system 100 includes a pre-combustionmodule 150 adapted to burn a portion of received crop 102 to releaseheat energy 152 prior to introduction into sucrose extraction module110. In these embodiments, received crop 102 optionally enters module140 instead of module 110 (not depicted).

Optionally, the crop is sugar cane and the burned portion is sugar caneleaves.

Optionally, the crop is sugar beet and the burned portion is beetleaves.

Various ways that heat energy 152 may be used are described hereinbelow.In some exemplary embodiments of the invention, pre-combustion module150 is provided as a flow through furnace. The pre-burned crop 156produced by pre-combustion module 150 is transferred to sucroseextraction module 110. The combustion residue 154 is removed andoptionally used to fertilize fields, for example fields producingreceived crop 102.

In those exemplary embodiments of the invention employing sugar cane,pre-burned crop 156 is analogous to “b&c” cane. In some exemplaryembodiments of the invention, implementation of a “prescribed burn” iseasier in pre-combustion module 150 than according to the previouslyknown practice of burning cane in fields. Alternatively or additionally,use of pre-combustion module 150 permits harvest of heat energy 152which is lost using previously known practice of burning cane in fields.

Depicted exemplary system 100 includes a sucrose refinery 160 adapted toproduce crystallized sucrose 162 from raw juice 114. Refinery 160 is aconventional sugar refinery adapted to handle the specific type of rawjuice 114 resulting from delivered crop 102. However, refinery 160 willproduce a lower yield per ton of received crop 102 due to the “residualsucrose” in partially processed crop 112.

In some exemplary embodiments of the invention, system 100 includes alignin de-acidification module 170 adapted to separate acid fromresidual lignin 124 to produce combustible (de-acidified) lignin 172 andrecovered acid 174. In some exemplary embodiments of the invention,recovered acid 174 contains sugars. According to various exemplaryembodiments of the invention recovered acid 174 can be routed tohydrolysis module 120 and/or acid recovery stream 132.

In some exemplary embodiments of the invention, system 100 includes alignin-combustion module 180 adapted to receive and burn combustiblelignin 172 to release heat energy 182. Various ways to use heat energy182 are described below.

Exemplary Crop Processing Method

FIG. 2 depicts a crop processing method according to some exemplaryembodiments of the invention indicated generally as 200. Depicted method200 includes providing 210 a harvested crop containing an amount ofsucrose and processing 220 the harvested crop to produce sugar juice 222containing sucrose and partially processed crop product 224 including atleast 2%, optionally at least 5% of the amount of sucrose originallyprovided 210 in the harvested crop. According to various exemplaryembodiments of the invention sugar juice 222 is processed to produce rawcrystalline sucrose or table sugar (crystalline sucrose) according toknown industrial methods. The industrial methods may vary to a certaindegree depending upon the nature of juice 222. The nature of juice 222may be influenced by the harvested crop and/or by the percentage ofsucrose remaining in partially processed crop product 224. According tovarious exemplary embodiments of the invention this percentage may be 2,5, 10, 15, 20, 25, 30, 35, 40% or intermediate or higher percentages. Insome exemplary embodiments of the invention, increasing the percentageof sucrose in partially processed crop product 224 contributes to anease of preparation and/or a reduced cost per unit of the table sugar.

According to various exemplary embodiments of the invention theharvested crop includes burned and cut (b&c) sugar cane and/or sugarcane with leaves and/or sugar beets. Optionally, the beets can be withor without leaves.

Exemplary Sugar Production Method

FIG. 3 depicts a sugar production method according to some exemplaryembodiments of the invention indicated generally as 300. Depicted method300 includes providing 310 a partially processed crop product containingat least 2%, optionally at least 5% of the sucrose content of the cropat harvest on a dry solids basis, cellulose and lignin. According tovarious exemplary embodiments of the invention the crop product may bederived from sugar cane or sugar beets. In those embodiments where sugarcane is employed, “% of the sucrose content” is optionally relative tothe amount in b&c cane.

In some exemplary embodiments of the invention, the partially processedcrop product is provided as a slurry including added water. In otherexemplary embodiments of the invention, the partially processed cropproduct is provided without added water.

Depicted method 300 includes hydrolyzing 320 the partially processedcrop product with HCl to produce an acid hydrolyzate stream 322 and alignin stream 324.

Optionally, lignin stream 324 is further processed to produce recoveredHCl (174; FIG. 1) and de-acidified lignin (172; FIG. 1). Optionally, aratio of HCl to lignin in de-acidified lignin 172 is less than 0.03 byweight. Details of exemplary processes for this further processing aredisclosed in co-pending U.S. provisional application 61/491,243 which isfully incorporated herein by reference.

Additional relevant processes for the hydrolysis of lignocelluloseutilizing concentrated HCl, de-acidification of the products andrecycling of the acid are described in greater detail in PCT applicationIL2010/001042 and/or IL2011/000130 and/or U.S. 61/491,243 and/or U.S.61/483,777 and/or U.S. 61/487,319. Each of these applications is fullyincorporated herein by reference.

In some exemplary embodiments of the invention, hydrolyzing 320 includescontacting the partially processed crop product provided at 310 with theHCl in a counter-current mode of operation. Suitable exemplaryhydrolysis systems and methods are disclosed in co-pending U.S.provisional applications 61/483,777 and 61/487,319 which are each fullyincorporated herein by reference.

In some exemplary embodiments of the invention, the counter-current modeof operation contributes to an ability to remove sugars resulting fromsucrose inversion prior to their degradation. Optionally, the sugarwhich is spared from degradation is fructose.

In some exemplary embodiments of the invention, hydrolysis 320 isconducted at a temperature lower than 30, optionally 25, optionally 20,optionally 15, optionally 12 degrees C. or intermediate or lowertemperatures. Optionally, a reduction in hydrolysis temperaturecontributes to a reduction in degradation of monosaccharides.

Optionally, lignin stream 324 contains HCl and/or sugars. In someexemplary embodiments of the invention, lignin stream 324 is subject tofurther processing to recover acid and/or sugars. Optionally, recoveredsugars are united with stream 322 or returned to hydrolysis 320 or addedto de-acidified sugar solution 332. Alternatively or additionally,recovered acid is optionally returned to hydrolysis 320.

Depicted method 300 also includes de-acidifying 330 hydrolyzate stream322 to produce a de-acidified sugar solution 332 and an HCl recoverystream 334. In some exemplary embodiments of the invention, de-acidifiedsugar solution 332 includes at least 90% of a theoretical yield ofsugars from the sucrose content of the partially processed crop productprovided at 310. In some exemplary embodiments of the invention,de-acidified sugar solution 332 includes at least 90% of a theoreticalyield of sugars from the cellulose content of the partially processedcrop product provided at 310. Sugar solution 332 includes sugarsproduced by hydrolysis of cellulose as well as monosaccharides producedby inversion of sucrose. Fructose can be employed as marker for sucrose.Fructose is sensitive to degradation by strong acids such asconcentrated HCl. Examples presented hereinbelow demonstrate thatfructose is not significantly degraded by HCL under appropriateconditions.

Degradation of hexoses by acid produces hydroxymethylfurfural. In someexemplary embodiments of the invention, a weight/weight ratio betweenhydroxymethylfurfural and sugars in acid hydrolyzate stream 322 is lessthan 0.01. Optionally, a weight/weight ratio betweenhydroxymethylfurfural and sugars in said de-acidified sugar solution isless than 0.002. In some exemplary embodiments of the invention,de-acidification 330 has the surprising effect of removing unwantedhydroxymethylfurfural.

Degradation of pentoses by acid produces furfural. In some exemplaryembodiments of the invention, a weight/weight ratio between furfural andsugars in acid hydrolyzate stream 322 is less than 0.01. Optionally, aweight/weight ratio between furfural and sugars in said de-acidifiedsugar solution 332 is less than 0.002. In some exemplary embodiments ofthe invention, de-acidification 330 has the surprising effect ofremoving unwanted furfural.

These ratios indicate that if hydrolysis 320 is conducted properly,degradation of sugars occurs at a low level. Alternatively oradditionally, these ratios indicate that an amount of undesirable sugardegradation products is not increased by de-acidification 330. Instead,it appears that de-acidification 330 separates unwanted degradationproducts from sugars. In some exemplary embodiments of the invention,de-acidifying 330 hydrolyzate 322 reduces a concentration of at leastone non-saccharide impurity (e.g., furfural) in the hydrolyzate by atleast 30% on a weight basis relative to the sugars.

In some exemplary embodiments of the invention, HCl recovery stream 334includes at least 95% of the HCl in acid hydrolyzate stream 322. In someexemplary embodiments of the invention, acid hydrolyzate stream 322 ischaracterized by a ratio of sugars to water in the range of 0.2 to 2.0by weight and a ratio of HCl to water of at least 0.17 by weight.Optionally, the ratio of HCl to water may be as high as 0.5, 0.55, 0.6,0.7, 0.75, 0.8 or 0.85 or an intermediate value by weight. According tovarious exemplary embodiments of the invention this ratio may varydepending upon how HCl recycling is conducted and/or where acidhydrolyzate stream 322 is removed from hydrolysis module 120 (FIG. 1).

Optionally, method 300 includes concentrating HCl from HCl recoverystream 334 to a concentration of at least 35% wt (not depicted). In someexemplary embodiments of the invention, this concentration is achievedby heating recovery stream 334 to produce gaseous HCl and absorbing thegaseous HCl in water or an aqueous solution.

Depicted exemplary method 300 includes collecting 340 gaseous HCl fromHCl recovery stream 334. Optionally, this collection involvesdistillation. Again, relevant details can be found in co-pending U.S.provisional applications 61/483,777 and 61/487,319 which are each fullyincorporated herein by reference.

In some exemplary embodiments of the invention, this gaseous HCl iscontacted 350 with the partially processed crop product (310) or withwater. Optionally, the crop product is provided as an aqueous slurry andwater from the slurry absorbs the gaseous HCl. In other words, HCl isrecycled and re-used in the process while the partially processed cropproduct flows through process.

Exemplary Sugar De-Acidification Method

FIG. 4 is a simplified flow diagram of a sugar de-acidification methodaccording to some exemplary embodiments of the invention indicatedgenerally as 400. The method relates to acid hydrolyzate stream 322 ofFIG. 3.

Depicted method 400 includes extracting 410 acid hydrolyzate stream 322with a first extractant including a first solvent (S1) to produce to anHCl-carrying first extract 412 and an HCl-depleted sugar solution 414.Depicted method 400 also includes recovering 420 HCl from HCl-carryingfirst extract 412. In some exemplary embodiments of the invention,recovery is via distillation. Optionally, recovered HCl is recycled(e.g. to hydrolyzing 320; FIG. 3). In some exemplary embodiments of theinvention, HCl-carrying first extract 412 is contacted with or mixedwith a recycled aqueous HCl solution, prior to recovering 420.

Exemplary Additional Sugar De-Acidification Methods

FIG. 5 is a simplified flow diagram of a supplementary sugarde-acidification method according to some exemplary embodiments of theinvention indicated generally as 500. The method relates to HCl-depletedsugar solution 414 of FIG. 4.

Depicted method 500 includes two alternatives. Each of thesealternatives can be employed to remove unacceptable levels of HClpresent in sugar solution 414.

In the first alternative a chromatographic separation 520 is applied toHCl-depleted sugar solution 414. In those exemplary embodiments of theinvention which employ chromatographic separation 520, sugar solution414 is separated into an HCl-containing “acid cut” 524 which is enrichedin disaccharides and higher oligosaccharides relative to totalsaccharides and a “monomer cut” 522 enriched in monosaccharides relativeto total saccharides. Monomer cut 522 is analogous to de-acidified sugarsolution 332 (FIG. 3) in that it contains only acceptably low levels ofresidual HCl. However, monomer cut 522 may contain a lower concentrationand/or a lower total amount of sugars than de-acidified sugar solution332. In some exemplary embodiments of the invention, monomer cut 522 hasan HCl/sugar ratio less than 0.03 by weight. Exemplary chromatographicseparation techniques are disclosed in co-pending application IL 211093which is fully incorporated herein by reference.

In some exemplary embodiments of the invention, chromatographicseparation 520 employs a purolite resin. Optionally, Purolite Resin PCR642H+(The Purolite Company, Bala Cynwood, Pa., USA)

In some exemplary embodiments of the invention, acid cut 524 is subjectto further treatment to separate saccharides from HCl and/or to adjust aratio of monosaccharides to total saccharides.

The second alternative employs an additional extraction 530 with asecond extractant including S1 and a second solvent (S2).

In those exemplary embodiments of the invention which employ asubsequent extraction 530, there is a selective transfer of HCl to thesecond extractant to form a second extract 534 and de-acidified sugarsolution 332 that has an HCl/sugar ratio less than 0.03 by weight.Exemplary subsequent extraction techniques are disclosed in co-pendingapplication PCT IL2011/000130 which is fully incorporated herein byreference.

Optionally, the extractant employed in extractions 410 (FIG. 4) and 530(FIG. 5) include a same S1 solvent and/or a different solvent. S1solvents employed in exemplary embodiments of the invention include, butare not limited to alcohols (e.g. hexanol and 2-ethyl hexanol), ketonesand aldehydes having at least 5 carbon atoms and combinations thereof.

In some exemplary embodiments of the invention, the second extractant ischaracterized by a delta-P greater than the delta-P of the firstextractant by at least 0.2 MPa^(1/2) and/or a delta-H greater than thedelta-H of the first extractant by at least 0.2 MPa^(1/2).

According to various exemplary embodiments of the invention, S2 includesat least one member selected from the group consisting of C₁-C₄ mono- orpoly-alcohols, aldehydes and ketones. Optionally, S2 includes acetone.

In some exemplary embodiments of the invention, S1 and S2 are eachrecycled and reused. Optionally, this recycling involves separaterecovery of S1 and S2 from a common distillation unit. This means thatat least a fraction of the first extractant is generated from an organicphase composition by removing S2 therefrom. If this occurs, it producesa removed S2-comprising stream and an S2-depleted extract. TheS2-depleted extract splits at 25° C. into an S2-depleted heavy phase andan S2-depleted light phase. This makes it possible to separate theS2-depleted heavy phase from the S2-depleted light phase.

As a result, the first extractant of extraction 410 may include someresidual S2. However, a ratio of S2:S1 in the second extractant ofextraction 530 is typically greater than a same ratio in the firstextractant of extraction 410 by at least 10%.

Additional Exemplary Sugar Production Method

FIG. 6 depicts an additional exemplary sugar production method accordingto some exemplary embodiments of the invention indicated generally as600. Depicted method 600 is similar to method 300 in many respects.Method 600 differs from method 300 primarily in that method 300 does notinclude any extraction of raw sugar juice (see 114 in FIG. 1) from thecrop prior to acid hydrolysis.

Depicted method 600 includes providing 610 a harvested sucrose cropcontaining sucrose, cellulose and lignin. According to various exemplaryembodiments of the invention the crop product may be derived from, forexample, sugar cane or sugar beets. In those embodiments where sugarcane is employed b&c cane can be employed although it may beadvantageous to use cane with leaves and/or tops.

Optionally, the harvested sucrose crop can be provided as a slurryincluding added water or an aqueous solution of HCl. In other exemplaryembodiments of the invention, the partially processed crop product isprovided without added liquid.

Depicted method 600 includes hydrolyzing 620 the harvested sucrose cropwith HCl to produce an acid hydrolyzate stream 322 and a lignin stream324.

Optionally, lignin stream 324 is further processed to produce recoveredHCl (174; FIG. 1) and de-acidified lignin (172; FIG. 1). Optionally, aratio of HCl to lignin in de-acidified lignin 172 is less than 0.03 byweight.

Details of exemplary processes for hydrolysis of lignocelluloseutilizing concentrated HCl, de-acidification of the products andrecycling of the acid are presented in a series of co-pendingapplications which are listed, and incorporated by reference, in thecontext of the text describing FIG. 3 hereinabove.

In some exemplary embodiments of the invention, hydrolyzing 620 includescontacting the harvested sucrose crop provided at 610 with the HCl in acounter-current mode of operation. Details of exemplary counter currentprocesses for hydrolysis are presented in co-pending applications whichare listed, and incorporated by reference, in the context of the textdescribing FIG. 3 hereinabove.

In some exemplary embodiments of the invention, the counter-current modeof operation contributes to an ability to remove sugars resulting fromsucrose inversion prior to their degradation. Optionally, the sugarwhich is spared from degradation is fructose.

In some exemplary embodiments of the invention, hydrolysis 620 isconducted at a temperature lower than 30, optionally 25, optionally 20,optionally 15, optionally 12 degrees C. or intermediate or lowertemperatures. Optionally, a reduction in hydrolysis temperaturecontributes to a reduction in degradation of monosaccharides.

Optionally, lignin stream 624 contains HCl and/or sugars. In someexemplary embodiments of the invention, lignin stream 624 is subject tofurther processing to recover acid and/or sugars. Optionally, recoveredsugars are united with stream 622 or returned to hydrolysis 620 or addedto de-acidified sugar solution 632. Alternatively or additionally,recovered acid is optionally returned to hydrolysis 620.

Depicted method 600 also includes de-acidifying 630 hydrolyzate stream622 to produce a de-acidified sugar solution 632 and an HCl recoverystream 634. De-acidifying 630 corresponds to de-acidifying 330 of method300 (FIG. 3). Exemplary details of de-acidifying 330 provided in thetextual description of FIGS. 4 and 5 hereinabove can also be applied tode-acidifying 630.

In some exemplary embodiments of the invention, de-acidified sugarsolution 632 includes at least 90% of a theoretical yield of sugars fromthe sucrose content of the harvested sucrose crop provided at 610.Alternatively or additionally, de-acidified sugar solution 632 includesat least 90% of a theoretical yield of sugars from the cellulose contentof the harvested sucrose crop provided at 610.

Sugar solution 632 includes sugars produced by hydrolysis of celluloseas well as monosaccharides produced by inversion of sucrose. Fructosecan be employed as marker for sucrose. Fructose is sensitive todegradation by strong acids such as concentrated HCl. Examples presentedhereinbelow demonstrate that under appropriate hydrolysis conditions,sucrose undergoes inversion to glucose and fructose, but the degree ofdegradation of these monomers is acceptably low.

Degradation of hexoses by acid produces hydroxymethylfurfural. In someexemplary embodiments of the invention, a weight/weight ratio betweenhydroxymethylfurfural and sugars in acid hydrolyzate stream 622 is lessthan 0.01. Optionally, a weight/weight ratio betweenhydroxymethylfurfural and sugars in de-acidified sugar solution 632 isless than 0.002. In some exemplary embodiments of the invention,de-acidification 630 has the surprising effect of removing unwantedhydroxymethylfurfural.

Degradation of pentoses by acid produces furfural. In some exemplaryembodiments of the invention, a weight/weight ratio between furfural andsugars in acid hydrolyzate stream 622 is less than 0.01. Optionally, aweight/weight ratio between furfural and sugars in de-acidified sugarsolution 632 is less than 0.002. In some exemplary embodiments of theinvention, de-acidification 630 has the surprising effect of removingunwanted furfural.

These ratios indicate that if hydrolysis 620 is conducted properly,degradation of sugars occurs at a low level. Alternatively oradditionally, these ratios indicate that an amount of undesirable sugardegradation products is not increased by de-acidification 630. Instead,it appears that de-acidification 630 separates unwanted degradationproducts from sugars. In some exemplary embodiments of the invention,de-acidifying 630 hydrolyzate 622 reduces a concentration of at leastone non-saccharide impurity (e.g., furfural) in the hydrolyzate by atleast 30% on a weight basis relative to the sugars.

In some exemplary embodiments of the invention, HCl recovery stream 634includes at least 95% of the HCl in acid hydrolyzate stream 622. In someexemplary embodiments of the invention, acid hydrolyzate stream 622 ischaracterized by a ratio of sugars to water in the range of 0.2 to 2.0by weight and a ratio of HCl to water of at least 0.17 by weight.Optionally, the ratio of HCl to water may be as high as 0.5, 0.55, 0.6,0.7, 0.75, 0.8 or 0.85 or an intermediate value by weight. According tovarious exemplary embodiments of the invention this ratio may varydepending upon how HCl recycling is conducted and/or where acidhydrolyzate stream 622 is removed from hydrolysis module 120 (FIG. 1).

Optionally, method 600 includes concentrating HCl from HCl recoverystream 634 to a concentration of at least 35% wt (not depicted). In someexemplary embodiments of the invention, this concentration is achievedby heating recovery stream 634 to produce gaseous HCl and absorbing thegaseous HCl in water or an aqueous solution.

Depicted exemplary method 600 includes collecting 640 gaseous HCl fromHCl recovery stream 634. Optionally, this collection involvesdistillation. Again, relevant details can be found in co-pending USprovisional applications cited and incorporated by reference in the textdescribing FIG. 3 hereinabove.

In some exemplary embodiments of the invention, this gaseous HCl iscontacted 650 with water. In other words, HCl is recycled and re-used inthe process while the harvested sucrose crop flows through process.

Referring now to FIG. 1, according to method 600, harvested sucrose crop(received crop 102) would be introduced directly into hydrolysis module120. There would be no attempt to produce juice 114. Instead, all of thesucrose in crop 102 is inverted to produce monosaccharides.

Exemplary Crop Specific Considerations; Sugar Cane

In some exemplary embodiments of the invention, a partially processedcrop product including at least 2%, optionally at least 5% of an amountof sucrose present in the harvested crop is provided.

In those exemplary embodiments of the invention where the crop is sugarcane, an amount of sucrose retained in the partially processed crop canbe regulated by controlling cane breaking and/or cane milling and/or anamount of imbibition water added during cane milling.

Optionally, reducing a degree of breaking and/or milling of the canecontributes to an increase in the amount of sucrose present in thepartially processed sugar cane product.

Conversely, increasing an amount of imbibition water added during canemilling contributes to a decrease in the amount of sucrose present inthe partially processed sugar cane product.

Some exemplary embodiments of the invention relate to controlling canebreaking and/or milling parameters to retain at least 2, optionally atleast 5% of sucrose available in the cane in what is generally referredto as “bagasse”.

Some exemplary embodiments of the invention relate to controlling anamount of imbibitions water to retain at least 2, optionally at least 5%of sucrose available in the cane in what is generally referred to as“bagasse”.

Exemplary Crop Specific Considerations: Sugar Beet

In some exemplary embodiments of the invention, a partially processedcrop product including at least 2, optionally at least 5% of an amountof sucrose present in the harvested crop is provided.

In those exemplary embodiments of the invention where the crop is sugarbeet, an amount of sucrose retained in the partially processed cropproduct can be regulated by controlling one or more diffusionparameters. Exemplary diffusion parameters include, but are not limitedto cossettes thickness, cossettes surface area: mass ratio, cossettesretention time, water retention time, water volume per mass of cossettesand water temperature.

Optionally, decreasing cossettes retention time contributes to anincrease in the amount of sucrose present in the partially processedsugar beet product.

Alternatively or additionally, reducing a temperature of water employedin diffusion contributes to an increase in the amount of sucrose presentin the partially processed sugar beet product.

Alternatively or additionally, increasing cossettes thickness and/ordecreasing a cossettes surface area: mass ratio contributes to anincrease in the amount of sucrose present in the partially processedsugar beet product.

Alternatively or additionally, decreasing water volume per mass ofcossettes in the diffuser contributes to an increase in the amount ofsucrose present in the partially processed sugar beet product.

Some exemplary embodiments of the invention relate to controlling one ormore cossette parameters to retain at least 2, optionally at least 5% ofsucrose available in the sugar beet in the cossettes after diffusion.

Some exemplary embodiments of the invention relate to controlling one ormore diffusion parameters to retain at least 2, optionally at least 5%of sucrose available in the sugar beet in the cossettes after diffusion.

Exemplary Sugar Juice Considerations

According to various exemplary embodiments of the invention raw juice114 (FIG. 1) will contain 5, 10, 15, 20, 25 or 30% or intermediate orgreater percentages less of the sucrose present in received crop 102than is typically accepted in the table sugar industry. In someexemplary embodiments of the invention, preparation of juice 114 withless sucrose than is typically accepted in the table sugar industrycontributes to a reduction in breaking and/or milling costs. In otherexemplary embodiments of the invention, preparation of juice 114 withless sucrose than is typically accepted in the table sugar industrycontributes to a reduction in diffusion costs and/or cost of cossettepreparation.

In some exemplary embodiments of the invention, juice 114 is moreconcentrated than analogous juice prepared in a conventional industrialprocess in which all of the sucrose is extracted from the crop.Optionally, a higher concentration of sucrose in juice 114 contributesto an increased yield during sugar crystallization at a plant producingraw sugar. Optionally, the increase is realized primarily in massecuiteA and/or B.

Alternatively or additionally, in some exemplary embodiments of theinvention, juice 114 is provided in a smaller total volume per ton ofcrop than is typically accepted in the table sugar industry. Optionally,a reduction in total volume of juice 114 contributes to decreased costsin production of raw sugar. According to various exemplary embodimentsof the invention this decreased cost can be related to decreasedmaterial inputs (e.g. lime and/or soluble phosphate) and/or decreasedenergy inputs. Decreased energy inputs may be realized, for example, inclarifiers and/or vacuum pans and/or centrifuges.

Alternatively or additionally, in some exemplary embodiments of theinvention, juice 114 may contain a smaller total amount and/or a lowerconcentration of one or more contaminants. Optionally, a smaller totalamount and/or a lower concentration of contaminants contribute to animprovement in efficiency of clarification and/or mud filtration.Exemplary contaminants include, but are not limited to, salts,carboxylic acids, amino acids, proteins, gums, waxes, fat andphosphatides. Sugar juice produced according to conventional practicesmay contain soluble solids which are 75-92% soluble sugars, with theremainder of the soluble solids being made up of various contaminants.

Exemplary Fructose Mixtures

Various exemplary embodiments of the invention demonstrate thefeasibility of producing commercially and/or industrially significantamounts of fructose by acid hydrolysis of sucrose. The resultantfructose is typically present as part of a mixture which includesglucose resulting from sucrose inversion as well as othermonosaccharides and/or disaccharides and/or higher oligosaccharidesresulting from hydrolysis of hemicelluloses and/or cellulose.

In some exemplary embodiments of the invention, such a mixture ischaracterized by a ratio of fructose to mannose of at least 0.4.Optionally, the ratio of fructose to mannose is less than about 4.8.

In some exemplary embodiments of the invention, such a mixture ischaracterized by a ratio of fructose to xylose of at least 0.4.Optionally, the ratio of fructose to mannose is less than about 4.6.

In some exemplary embodiments of the invention, such a mixture ischaracterized by a ratio of fructose to galactose of at least 0.3.Optionally, the ratio of fructose to galactaose is less than about 3.2.

In some exemplary embodiments of the invention, such a mixture ischaracterized by a ratio of fructose to arabinose of at least 1.0.Optionally, the ratio of fructose to arabinose is less than about 11.

In some exemplary embodiments of the invention, such a mixture ischaracterized by a ratio of fructose to total dimeric sugars of at least0.05. Optionally, a ratio of fructose to total dimeric sugars is lessthan about 0.6.

In some exemplary embodiments of the invention, such a mixture ischaracterized by a ratio of fructose to total monomeric sugars of atleast 0.023. Optionally, the ratio of fructose to total monomeric sugarsis less than about 0.2.

Optionally, such a mixture includes hydroxymethylfurfural (HMF).

In some exemplary embodiments of the invention, such a mixture isprovided as part of a culture medium. The mixture can serve as an energysource and/or a trigger for an inducible promoter. In some exemplaryembodiments of the invention, an organism is grown in the mediacontaining the mixture to produce a fermentation production.

Exemplary Crop Development Considerations

Development of new strains of sucrose crops has traditionallyconcentrated on sucrose yield per unit of cultivated land. In light ofthe instant specification, it may be attractive to develop crops whichhave a maximum yield of total biomass (sucrose plus cellulose pluslignin) per unit of cultivated land.

Optionally, an integrated approach to production of sucrose crystalstogether with hydrolysis of cellulose to produce an additional sugarmixture (as described in the context of system 100 and/or method 300)may make it feasible to grow “low sucrose” crops profitably.

Alternatively or additionally, an “all hydrolysis” approach as describedin the context of method 600 may provide an alternative to the sucroseindustry which would favor “low sucrose” crops.

A shift from high sucrose to low sucrose strains of relevant crops canbe accomplished using conventional crop husbandry techniques and/orgenetic engineering/molecular biology techniques.

Exemplary Flow Control Considerations

In some exemplary embodiments of the invention flow control mechanismsare used to transport solids, slurries or liquids. Exemplary flowcontrol mechanisms include, but are not limited to pumps and mechanicaltransport mechanisms. Because they are not central to the primaryobjectives of the described exemplary embodiments, these flow controlmechanisms are not depicted in the drawings.

Optionally, pumps are used to transport liquids or slurries. Forexample, partially processed crop product 112 (FIG. 1) can be providedas a sugar cane bagasse or wet cossettes of sugar beet after diffusion.Such a partially processed crop product 112 may be transported by a pumpto hydrolysis module 120. Alternatively or additionally, raw juice 114may be pumped to sucrose refinery 160. Alternatively or additionally,extractant 142 may be pumped to module 140. Alternatively oradditionally, acid hydrolyzate 122 may be pumped to acid recovery module130. Alternatively or additionally, acid recovery stream 132 and/orrecovered HCl 174 may be pumped to hydrolysis module 120. Alternativelyor additionally, de-acidified hydrolyzate 134 may be pumped to adownstream processing facility and/or storage tank (not depicted).Alternatively or additionally, residual lignin 124 may be pumped tolignin de-acidification module 170. Alternatively or additionally, ash144 may be provided in a pumpable liquid extract.

Alternatively or additionally, mechanical transport mechanisms (e.g.conveyors such as belts or augers) are optionally used to transportsolids or slurries containing a high solids concentration. For example,received crop 102 may be transported by a conveyor belt to sucroseextraction module 110. Alternatively or additionally, partiallyprocessed crop product 112 is provided as a slurry which is transferredto hydrolysis module 120 using a conveyor belt and/or auger.

Alternatively or additionally, lignin may be handled by augers and/orconveyors (e.g. belts) and/or centrifuges within lignin de-acidificationmodule 170 and/or de-acidified lignin 172 may be transported tocombustion module 180 using augers and/or conveyors.

Alternatively or additionally, pre-burned crop and/or pre-extracted crop146 may be handled by augers and/or conveyors.

Exemplary Uses for Heat Energy

FIG. 1 depicts heat energy 182 released from de-acidified lignin 172 inlignin combustion module 180. It is significant that even aftersubstantially all of the hemicellulose and cellulose from the harvestedcrop has been hydrolyzed, de-acidified lignin 172 still contains enoughheat energy 182 to be industrially useful. Some exemplary embodiments ofthe invention relate to utilization of energy 182.

According to various exemplary embodiments of the invention heat energy182 can be used for processing 220 (FIG. 2) the harvested crop and/orrefining of sucrose from a sugar juice produced during processing 220and/or distillation.

According to various exemplary embodiments of the invention thedistillation can be in the context of de-acidification 330 (FIG. 3) ofhydrolyzate and/or de-acidification of lignin to recover HCl and/orsolvent (e.g. S1 and/or S2) and/or water.

FIG. 1 also depicts heat energy 152 released from leaves inpre-combustion module 150.

In some exemplary embodiments of the invention, the partially processedcrop product is produced from unburned sugar cane. Conventional caneharvesting practice typically includes burning of leaves and tops in thefield either before or after cutting the cane.

In other exemplary embodiments of the invention, the partially processedcrop product is produced from sugar beets without removal of leaves.

In some exemplary embodiments of the invention, the partially processedcrop product 112 is brought to the plant with leaves which are burned torelease heat energy 152 and ashes 154 as well as pre-burned crop 156.Since the combustion is incomplete by design, ashes 154 are differentfrom “ash” produced by complete combustion in that ashes 154 willcontain residual organic matter.

In some exemplary embodiments of the invention, heat energy 152 is usedfor similar purposes as those described above for heat energy 182.

Alternatively or additionally, heat energy 152 and/or 182 can be used togenerate electric power.

Alternatively or additionally, at least a portion of ashes 154 are usedto fertilize a field.

Optionally, the field is one in which received crop 102 has been grownor will be grown.

Exemplary Departure from Accepted Industrial Process

In the cane sugar industry it is widely believed that field burning ofleaves is an important part of the sugar production process.Specifically, it is believed that there is an actual reduction insucrose yield of three pounds per gross ton of sugar cane for every 1%of leaves and tops processed (Louisiana cooperative extension service;publication 2820 (2M) 9/00).

However, cane or beet leaves and cane tops are rich in cellulose and canproduce additional sugars when hydrolyzed. In some exemplary embodimentsof the invention, sugar production efficiency is increased by bringingcellulose rich leaves and/or tops to the plant. Since the leavesrepresent a significant portion of the available biomass, they have thepotential to make a significant contribution to total sugar yield inacid hydrolyzate 322 (FIG. 3) if they are hydrolyzed 320.

In contrast to many other potential substrates for acid hydrolysis,leaves from sugar cane and sugar beet have no “high value” alternativeuse.

Exemplary Modifications

In some exemplary embodiments of the invention, a stream, fraction orextract is described as being extracted. According to various exemplaryembodiments of the invention this extraction may be on the stream,fraction or extract per se or on a modified stream, fraction or extract.Optional modifications include, but are not limited to, dilution,concentration, mixing with another stream, fraction or extract,temperature adjustment, and filtration. Optionally, two or moremodifications may be performed prior to extraction.

Exemplary Fructose Production Method

FIG. 7 is a simplified flow diagram of a method for fructose productionaccording to some exemplary embodiments of the invention indicatedgenerally as method 700. Depicted exemplary method 700 includesproviding 710 a substrate including cellulose. Optionally, the substrateincludes sucrose 712. According to various exemplary embodiments of theinvention the substrate may be, for example, sugar cane or sugar beetsand/or wood. Optionally, the cane or beets can be partially processed toremove a portion of their sucrose as described above.

Depicted method 700 includes hydrolyzing 720 the substrate with HCl toproduce an acid hydrolyzate stream 722. This hydrolyzing is similar tothat described hereinabove, for example in the context of FIG. 3.

Depicted method 700 includes de-acidifying 730 hydrolyzate stream 722 toproduce a de-acidified sugar solution 732 and an HCl recovery stream734. de-acidifying 730 is similar to the de-acidification proceduresdescribed hereinabove in the context of FIGS. 3, 4 and 5.

Depicted method 700 includes enzymatically converting 740 at least aportion of glucose in de-acidified sugar solution 732 to produce afructose enriched sugar solution 742. Since available enzymes arecurrently limited to an efficiency of about 42%, fructose enriched sugarsolution 742 still contains unconverted glucose.

In some exemplary embodiments of the invention, method 700 includeschromatographically separating 750 fructose enriched sugar solution 742to produce a fructose cut 752 and a glucose cut 754. Optionally, glucosecut 754 is recycled to another round of enzymatic concersion 740 asindicated by the upward pointing arrow. Optionally, this recycling canbe repeated until substantially all of the glucose has been converted tofructose.

According to various exemplary embodiments of the invention fructose cut752 can optionally be subjected to further purification steps and/orconcentrated and/or crystallized.

The total yield of fructose per unit of substrate will vary according tothe amount of sucrose 712 and/or a degree of completion of hydrolysis720 and/or an efficiency of enzymatic conversion 740 and/or a number oftime that glucose cut 754 is recycled to enzymatic conversion 740.

Underlying Rationale

Various exemplary embodiments of the invention described above are basedupon the understanding that in the table sugar industry, processing torecover a first fraction of refined sucrose is easy and therefore of lowcost while each subsequent fraction carries an increased cost per unit.Increasing the refined sucrose yield requires extra costs, for examplecosts related to increased energy input. The increased energy input istypically related to increased dilution and subsequent sugar recovery.Alternatively or additionally, increasing the refined sucrose yield islimited by product losses in crystallization and/or attempts to separateimpurities from the sucrose.

This specification demonstrates that it is industrially feasible topurposely recover only a fraction of the sucrose in the crop ascrystalline sucrose. The justification for this comes from increasedtotal saccharide yields in hydrolysis of the residual crop product (e.g.bagasse or cossettes) containing the “discarded” sucrose.

Although acid hydrolysis of lignocellulosic material was previouslydescribed, it was previously presumed that acid hydrolysis would lead torapid degradation of sucrose. Data presented in the Examples sectionbelow demonstrates that this presumption is not necessarily correct.

It is expected that during the life of this patent many sucrose refiningprocesses will be developed and the scope of the invention is intendedto include all such new technologies a priori.

It is expected that during the life of this patent many enzymaticprocesses for conversion of glucose to fructose and/or chromatographicseparation methods to separate glucose from fructose will be developedand the scope of the invention is intended to include all such newtechnologies a priori.

As used herein the term “about” refers to ±10% and includes, ±1% as wellas ±0.1%.

Although the invention has been described in conjunction with specificembodiments thereof, it is evident that many alternatives, modificationsand variations will be apparent to those skilled in the art.Accordingly, it is intended to embrace all such alternatives,modifications and variations that fall within the spirit and broad scopeof the appended claims.

Specifically, a variety of numerical indicators have been utilized. Itshould be understood that these numerical indicators could vary evenfurther based upon a variety of engineering principles, materials,intended use and designs incorporated into the invention. Additionally,components and/or actions ascribed to exemplary embodiments of theinvention and depicted as a single unit may be divided into subunits.Conversely, components and/or actions ascribed to exemplary embodimentsof the invention and depicted as sub-units/individual actions may becombined into a single unit/action with the described/depicted function.

Alternatively, or additionally, features used to describe a method canbe used to characterize an apparatus and features used to describe anapparatus can be used to characterize a method.

It should be further understood that the individual features describedhereinabove can be combined in all possible combinations andsub-combinations to produce additional embodiments of the invention. Theexamples given above are exemplary in nature and are not intended tolimit the scope of the invention which is defined solely by thefollowing claims. Specifically, the invention has been described in thecontext of acid hydrolysis using HCl but might also be used with otherstrong acids (e.g. sulfuric acid and/or nitric acid).

All publications, patents and patent applications mentioned in thisspecification are herein incorporated in their entirety by referenceinto the specification, to the same extent as if each individualpublication, patent or patent application was specifically andindividually indicated to be incorporated herein by reference. Inaddition, citation or identification of any reference in thisapplication shall not be construed as an admission that such referenceis available as prior art to the present application.

The terms “include”, and “have” and their conjugates as used herein mean“including but not necessarily limited to”.

Additional objects, advantages, and novel features of variousembodiments of the invention will become apparent to one ordinarilyskilled in the art upon examination of the following examples, which arenot intended to be limiting. Additionally, each of the variousembodiments and aspects of the present invention as delineatedhereinabove and as claimed in the claims section below findsexperimental support in the following examples.

EXAMPLES

Reference is now made to the following examples, which together with theabove descriptions; illustrate the invention in a non limiting fashion.

Example 1 Saccharide Composition of Hydrolyzate Prepared fromConventional Sugar Cane Bagasse

In order to establish a baseline composition for hydrolyzate compositionin terms of specific sugars, a de-acidified hydrolyzate prepared fromconventional sugar cane bagasse was analyzed.

The bagasse hydrolyzate was produced by processing the bagasse in a sixstage hydrolysis reactor series in a counter-current operation asdescribed in co-pending U.S. provisional application 61/48377 filed May9, 2011 and entitled “Hydrolysis systems and methods which is fullyincorporated herein by reference.

Briefly, an aqueous solution of 42% HCl was introduced continually at atemperature of 10-15° C. for 24 hours. The hydrolyzate was collected,HCl was removed by extraction and the de-acidified hydrolyzate wasconcentrated to give a sugar composition.

The composition was analyzed by HPLC (Varian Prostar® and a RezexRSO-Oligosaccharide Ag+, 10×200 mm column and pre-column) at 80° C.,Mobile Phase: Water (HPLC grade), Flow Rate: 0.3 mL/min, Injection:5-10ƒL (depending on sugars conc.), Detector: RI, Detector Temp.: 40° C.The DP groups HPLC results are given in area %, the x-axis in the graphsrepresents time (hrs.) and the y-axis area %.

Total monosaccharide content in the bagasse hydrolyzate was 70.2% oftotal saccharides present. Analysis results of monosaccharides aresummarized in Table 1. The results are calculated as % from sample'srefractive total saccharides (%/RTS).

TABLE 1 results of monosaccharides in hydrolyzate of sugar cane bagasseArabinose Galactose Xylose Mannose Glucose Fructose Sum 2.2 7.2 4.9 4.848.7 2.4 70.2

Results presented in Table 1 demonstrate that little, if any, sucrose ispresent in conventional sugar cane bagasse as indicated by the smallamount of fructose. Essentially all of the glucose in the hydrolyzate isproduced by hydrolysis of cellulose.

Example 2 Inversion of Sucrose in the Presence of HCL

In order to examine the effect of concentrated HCL on sucrose, anaqueous solution containing 1% Sucrose and 35% HCl was prepared underrefrigeration.

Sucrose was dissolved in water and placed in a beaker containing icewhich was stored at −20 degrees C. for approximately 5-10 min to producea sucrose solution.

An HCl solution (42.7% HCl was used) was weighed into a 50 ml roundbottom flask inside a beaker containing ice and was also stored at −20degrees C. for approximately 2-3 min.

The HCl solution was added to the sucrose solution while still cold andthe resultant acidified sucrose mixture was shaken 3 times and put backinto a beaker containing ice. Samples from this solution were taken into4 ml vial (also kept on ice) and transferred to a “mock hydrolysis” at11° C. for 6 hr. These conditions were selected to mimic those whichsucrose would be likely to encounter in a hydrolysis reactor asdescribed in Example 1.

At the end of the mock hydrolysis the vial was transferred into a beakercontaining ice and then to −20 degrees C. Analyses of monosaccharideswas as in Example 1. Analysis of hydroxymethylfurfural was by UVSpectrophotometry.

Results presented in Table 2 indicate that substantially all of thesucrose dimers were inverted to produce glucose and fructose monomers.Hydroxymethylfurfural (HMF) results from degradation of hexoses,especially fructose.

If no degradation occurred, a 52.6% yield of glucose and a corresponding52.6% yield of fructose would be expected (water is incorporated intothe sugar during inversion). The presence of HMF indicates that somedegradation occurred and the shift in monomeric hexose ratios in favorof glucose suggests that primarily fructose was degraded. Approximately1% of the total fructose appears to have been degraded.

The overall amount of degraded hexose was low, as indicated by the HMFconcentration. The apparent stability of hexoses in highly concentratedHCl after 6 hours is surprising.

TABLE 2 Analysis of sucrose and its products after mock hydrolysis with42.7% HCl at 11 degrees C. % Sucrose % Glucose % Fructose % HMFdecomposition formation formation formation 100% 51.8% 48.2% 0.038%

These results confirm that is feasible to incorporate sucrose into ahydrolysis reaction and receive an increased yield of monomeric sugarsin the resultant hydrolyzate.

Example 3 Saccharide Composition of Hydrolyzate Prepared from SucroseEnriched Sugar Cane Bagasse

This hypothetical example projects the results of hydrolysis conductedas in Example 1 using sucrose rich bagasse prepared according to variousexemplary embodiments of the invention. Hypothetical results aresummarized in Table 3. Each of hypothetical sample numbers 1 through 5presumes a 100 kg input of “bagasse” based upon combination of resultsfrom example 1 and 2 above.

Sample 1 is a standard bagasse of the type described in example 1,containing substantially no sucrose. Samples 2 through 5 presume bagassecontaining added sucrose from 5% to 30% as indicated. According tovarious exemplary embodiments of the invention this sucrose would beadded by modifying initial processing of the cane to cause acorresponding amount of sucrose to remain in the “bagasse” portion. Thismaterial is referred to throughout the specification as “partiallyprocessed” crop product.

The hypothetical results presume that the relative yields of glucose andfructose are as presented in Table 2 and that substantially all of theHMF results from fructose degradation. Results are presented as bothkilograms of yield and as % from sample's refractive total saccharides(in parentheses).

Hypothetical results summarized in Table 3 suggest that using theteachings of the instant specification it is possible to achieve higheryields of monosaccharides than previously possible from hydrolysis ofsugar cane bagasse. Total monosaccharide yield is increased by slightlymore than 1 kilogram for each kilogram of sucrose provided in thebagasse. The observed “excess” yield results from water incorporatedduring inversion.

TABLE 3 Hypothetical results of monosaccharides in hydrolyzate of sugarcane bagasse enriched with various levels of sucrose Arabinose GalactoseXylose Mannose Glucose Fructose Amount Kg Kg Kg Kg Kg Kg Total Totaladded (% of (% of (% of (% of (% of (% of monomers dimers No. sucrose %total) total) total) total) total) total) Kg Kg 1 0 1.7 5.5 3.8 3.7  37.5 1.8 77 35 (2.2) (7.2) (4.9) (4.8) (49) (2.4) 2 5 1.7 5.5 3.8 3.740 4.4 82 35 (2.1) (6.7) (4.6) (4.5) (49) (5.4) 3 10 1.7 5.5 3.8 3.7 437   87.5 35 (1.9) (6.3) (4.5) (4.3) (49) (8)   4 20 1.7 5.5 3.8 3.7 4812.3  98 35 (1.7) (5.6) (3.9) (3.8) (49) (12.6)  5 30 1.7 5.5 3.8 3.7 5317.5  109 35 (1.6) (5.0) (3.5) (3.4) (49) (16.1) 

The possibility for specific enrichment of glucose and fructose is ofcommercial interest. Each of these sugars is potentially valuable indownstream fermentation reactions to convert to other products.

Glucose yield increases in absolute terms, but remains essentiallyconstant in relative terms.

Fructose yield increases in both absolute terms and in relative terms.

These results indicate for the first time a way to increase fructoseconcentrations in acid hydrolyzates of lignocellulosic substrates.

Similar results would be expected using sugar beets instead of sugarcane.

Alternatively or additionally, it is expected that additional inputs(beyond 30%) of sucrose would provide proportionately greater yields ofglucose and fructose.

Example 4 Increasing Fructose Yield from Hydrolyzate Prepared fromSucrose Enriched Sugar Cane Bagasse

This hypothetical example demonstrates how to increase fructose yieldsfrom mixtures as set forth in Table 3 of Example 3 above

Fructose has a higher value than glucose because it is more reactive. Inthe Exemplary mixtures set forth hereinbelow in Table 3, the amount offructose relative to total monosaccharides is low (5.4 to 16.1% forsamples 2 through 5 respectively).

However, the amount of glucose relative to total monosaccharides is high(49% for samples 2 through 5). Despite this fixed ratio, the amount ofglucose in samples 2 through 5 increases progessively from samples 2through 5.

Conversion of glucose to fructose via enzymatic processes is routinelypracticed in the corn wet milling industry to produce high fructose cornsyrup. One of ordinary skill in the art will be familiar with therelevant enzymatic processes. Typically, a single round of enzymaticconversion, if conducted efficiently, converts about 42% of the glucoseto fructose. It is well accepted in the industry to separate glucosefrom fructose and subject the residual glucose to one or more additionalrounds of enzymatic conversion, so that the final yield of fructose fromglucose can approach 100%. Again, one of ordinary skill in the art willbe familiar with the relevant chromatographic processes.

If these processes were to be applied to the sugar mixture resultingfrom sample 2 in Table 3 the percentage of fructose relative to totalmonosacharides would increase significantly. If the conversion ofglucose to fructose were 25% efficient, fructose would account for about17.5% of the total monosaccharides. If the conversion of glucose tofructose were 50%, 75% or 100% efficient, fructose would account forabout 29.7, 42% or 54% of the total monosaccharides respectively.

If these processes were to be applied to the sugar mixture resultingfrom sample 5 in Table 3 the percentage of fructose relative to totalmonosacharides would increase more significantly. If the conversion ofglucose to fructose were 25% efficient, fructose would account for about28.2% of the total monosaccharides. If the conversion of glucose tofructose were 50%, 75% or 100% efficient, fructose would account forabout 40.4%, 52.5% or 64.7% of the total monosaccharides respectively.

In terms of absolute sucrose yield, 100% conversion of the glucose insample 2 would increase the total fructose yield from 4.4 to 44.4kilograms.

Similarly 100% conversion of the glucose in sample 5 would increase thetotal fructose yield from 17.54 to 70.5 kilograms.

These hypothetical results suggest that the various exemplaryembodiments of the invention described hereinabove offer an importantnew source of fructose.

The invention claimed is:
 1. A hydrolysate mixture of sugarscharacterized by a ratio of fructose to mannose of at least 0.4, whereinsaid hydrolysate mixture further comprises hydroxymethylfurfural.
 2. Thehydrolysate mixture of sugars according to claim 1, characterized inthat said ratio of fructose to mannose does not exceed 4.8.
 3. Thehydrolysate mixture of sugars according to claim 1, furthercharacterized by a ratio of fructose to total dimeric sugars of at least0.05.
 4. The hydrolysate mixture of sugars according to claim 3,characterized in that said ratio of fructose to total dimeric sugarsdoes not exceed 0.6.
 5. A hydrolysate mixture of sugars characterized bya ratio of fructose to xylose of at least 0.4, wherein said hydrolysatemixture further comprises hydroxymethylfurfural.
 6. The hydrolysatemixture of sugars according to claim 5, characterized in that said ratioof fructose to xylose does not exceed 4.6.
 7. The hydrolysate mixture ofsugars according to claim 6, further characterized by a ratio offructose to galactose of between 0.3 and 3.2.
 8. The hydrolysate mixtureof sugars according to claim 7, further characterized by a ratio offructose to total monomeric sugars of between 0.023 and 0.2.
 9. Thehydrolysate mixture of sugars according to claim 6, furthercharacterized by a ratio of fructose to total monomeric sugars ofbetween 0.023 and 0.2.
 10. A hydrolysate mixture of sugars characterizedby a ratio of fructose to galactose of at least 0.3, wherein saidhydrolysate mixture further comprises hydroxymethylfurfural.
 11. Thehydrolysate mixture of sugars according to claim 10, characterized inthat said ratio of fructose to galactose does not exceed 3.2.
 12. Ahydrolysate mixture of sugars characterized by a ratio of fructose toarabinose of at least 1.0, wherein said hydrolysate mixture furthercomprises hydroxymethylfurfural.
 13. The hydrolysate mixture of sugarsaccording to claim 12, characterized in that said ratio of fructose toarabinose does not exceed
 11. 14. A hydrolysate mixture of sugarscharacterized by a ratio of fructose to total monomeric sugars of atleast 0.023, wherein said hydrolysate mixture further compriseshydroxymethylfurfural.
 15. The hydrolysate mixture of sugars accordingto claim 14, characterized in that said ratio of fructose to totalmonomeric sugars does not exceed 0.2.
 16. The hydrolysate mixture ofsugars according to claim 14, characterized by a ratio of fructose tomannose of at least 0.4.
 17. The hydrolysate mixture of sugars accordingto claim 14, characterized by a ratio of fructose to xylose of at least0.4.
 18. The hydrolysate mixture of sugars according to claim 14,characterized by a ratio of fructose to galactose of at least 0.3.
 19. Amethod comprising: (a) providing a fermentor; and (b) fermenting amedium comprising the hydrolysate mixture of sugars according to any oneof claim 1, 5, 10, 12, or 14 in the fermentor to produce a fermentationproduct.
 20. An acid hydrolysate mixture of sugars characterized by aratio of fructose to mannose of at least 0.4, wherein the acidhydrolysate mixture of sugars was produced by contacting a partiallyprocessed crop with an acid.